"eVolatilitator" is a software specially designed to automatically calculate the historical volatility in any period for any stock so long as its historical stock price info is available on Yahoo! Finance. Although most of its functions are available on Option123 software , "eVolatilitator" provides another simple way to calculate historical volatility of stock/indexes. What you need is MS Excel and Internet access. You simply pick a stock, select a period to download historical stock price info, and enter the time period over which you want to calculate historical volatility, Here is the screenshot of eVolatilitator:

Pick a company you want to calculate historical volatility

Select a period in which the company's historical stock price info to be downloaded

In "Measurement Date" column, enter a measurement date which you want to calculate historical volatility: